In this paper we use "ring changed'' Gorenstein homologicaldimensions to define Cohen-Macaulay injective, projective and flatdimensions. For doing this we use the amalgamated duplication of thebase ring with semi-dualizing ideals. Among other results, we prove that finiteness of these new dimensions characterizes Cohen-Macaulay rings with dualizing ideals.

We consider a notion of sequential functional of -nite type, more generous than the familiar notion embodied in Plotkin’s language PCF. We study both the “full” and “e4ective” partial type structures arising from this notion of sequentiality. The full type structure coincides with that given by the strongly stable model of Bucciarelli and Ehrhard; it has also been characterized by van Oosten in...

In auctions where a seller can post a reserve price but if the object fails to sell cannot commit never to attempt to resell it, revenue equivalence between repeated first price and second price auctions without commitment results. When the time between auctions goes to zero, seller expected revenues converge to those of a static auction with no reserve price. With many bidders, the seller equi...

We investigate classes of Boolean algebras related to the notion of forcing that adds Cohen reals. A Cohen algebra is a Boolean algebra that is dense in the completion of a free Boolean algebra. We introduce and study generalizations of Cohen algebras: semi-Cohen algebras, pseudo-Cohen algebras and potentially Cohen algebras. These classes of Boolean algebras are closed under completion.

‎in this paper we study the existence of fixed points for mappings defined on complete metric spaces‎, ‎satisfying a general contractive inequality depending on two additional mappings‎.

Cyclical choice is persistently observed in experimental evidence. It typically occurs in simple decision problems (involving only binary comparisons and few alternatives) and in significant proportions, sometimes nearing or even exceeding 50 percent. This is obviously incompatible with the classical model of ratio­ nal choice, in which choice is constructed as the maximizer of a single prefere...

This paper defines the grammar class of sequentially indexed grammars. Sequentially indexed grammars are the result of a change in the index stack handling mechanism of indexed grammars [Aho68, Aho69]. Sequentially indexed grammars are different from linear indexed grammars [Gaz88]. Like indexed languages, sequentially indexed languages are a fully abstract language class. Unlike indexed langua...